Investigation of the frequency dependence of Barkhausen emissions for measuring the depth dependence of magnetic properties

Abstract

Discontinuous displacement of Bloch walls and discontinuous domain rotation are two of the mechanisms which contribute to Barkhausen emissions. Measurements of the pulse height spectra and root mean square ac amplitude of the emissions have been used to investigate the depth dependence of magnetic properties. An ac exciting field was superimposed on a constant dc field and the Barkhausen emissions were analyzed at different dc field strengths. The depth of penetration of the ac field, and hence the depth of the Barkhausen emissions, is controlled by the skin depth.